Composite hydrogel and uses thereof

Abstract

A composite hydrogel includes gelatin, cinnamic acid, polydopamine nanoparticles, and curcumin is provided. The gelatin is chemically cross-linked with the cinnamic acid to form cinnamic acid-modified gelatin (GelCA), and the curcumin is non-covalently linked to the polydopamine nanoparticles to form curcumin-loaded polydopamine nanoparticles (Cur@PDA). The GelCA undergoes a photo-crosslinking process and then binds with the Cur@PDA to form the composite hydrogel. A method for treating retinal tissue damage includes administering to a subject in need thereof an effective amount of the composite hydrogel.

What is claimed is: 
     
         1 . A composite hydrogel, comprising:
 a gelatin;   a cinnamic acid;   a plurality of polydopamine nanoparticles; and   a curcumin;   wherein the gelatin is chemically cross-linked with the cinnamic acid to form a cinnamic acid-modified gelatin, and the curcumin is linked by a non-covalent binding method to the polydopamine nanoparticles to form a plurality of curcumin-loaded polydopamine nanoparticles, the cinnamic acid-modified gelatin undergoes a photo-crosslinking reaction and then binds with the curcumin-loaded polydopamine nanoparticles to form the composite hydrogel.   
     
     
         2 . The composite hydrogel as claimed in  claim 1 , wherein the gelatin is chemically cross-linked with the cinnamic acid by a chemical crosslinking agent forming an amide bond between the carboxyl group of the cinnamic acid and an amino group of the gelatin to form a covalent bond. 
     
     
         3 . The composite hydrogel as claimed in  claim 2 , wherein the chemical crosslinking agent is 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC). 
     
     
         4 . The composite hydrogel as claimed in  claim 1 , further comprising a photoinitiator and a deionized water, and wherein the photoinitiator is lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP). 
     
     
         5 . The composite hydrogel as claimed in  claim 4 , wherein the photo-crosslinking reaction is initiated by an ultraviolet irradiation of the photoinitiator and generates a photo-dimerization reaction at the alkene functional group in the cinnamic acid-modified gelatin. 
     
     
         6 . The composite hydrogel as claimed in  claim 1 , wherein the polydopamine nanoparticles are formed through the self-polymerization of a dopamine. 
     
     
         7 . The composite hydrogel as claimed in  claim 1 , wherein based on the total weight of the composite hydrogel, the weight percentage of the curcumin-loaded polydopamine nanoparticles is less than 10 wt %. 
     
     
         8 . The composite hydrogel as claimed in  claim 1 , wherein the non-covalent binding method includes-x stacking and hydrogen bonding. 
     
     
         9 . The composite hydrogel as claimed in  claim 1 , wherein the composite hydrogel is injectable. 
     
     
         10 . A method for treating retinal tissue damage, comprising administering to a subject in need thereof an effective amount of the composite hydrogel of  claim 1 .